Photometry is a material concentration analysis method established on the basis of selective light absorption of materials, and is one of popular instrumental analysis methods at present. The theoretical foundation of photometry is the Lamber-Beer Law. Most existing photometric analyzers employ a single-wavelength and single-channel detection system. Owing to the technical characteristics of photometry, single-wavelength photometric detection may be affected by the noise, drifting, and contamination of the instrument, causing errors in the detection result. In addition, in a single-channel detection system, the cuvette or light source has to be replaced in the operation to obtain acceptable detection result. Therefore, such a system has drawbacks such as complex operation and troublesome switching, and can't meet the demand for accurate, rapid, and efficient detection.